Musical instrument



8, 1953 w. J. ANDERSON 2,649,007

MUSICAL INSTRUMENT Filed March 18, 1950 I 3 Sheets-Sheet l V Xii Aug. 18, 1953 w ANDERSON 2,649,007

MUSICAL INSTRUMENT Filed March 18, 1950 3 Sheets-Sheet 2 53 I ,5 aw. W 5260x15 j t Aug. 18, 1953 w. J. ANDERSON 2,549,007

MUSICAL INSTRUMENT Filed March 18, 1950 3 SheetsSheer, 5

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Patented Aug. 18, 1953 MUSICAL INSTRUMENT Walter J. Anderson, Elgin, Ill., assignor, by mesne assignments, to Central Commercial Industries, Inc., Chicago, 111., a corporation of Delaware Application March 18, 1950, Serial No. 150,506

4 Claims. (01. 84-172) This invention relates to keyboard musical instruments and more particularly to a combined instrument of the class disclosed in United States Letters Patent No. 2,250,065 wherein means actuable from a common keyboard are provided for producing sustained organ-like tones bearing the pitch relation to notes of a musical scale. The keyboard disclosed in said patent constitutes a part of a piano and the means combined therewith for producing sustained organ-like tones consists of any well known system of electron discharge devices providing sources of audio tone signals at pitche corresponding with the vibration frequencies of notes associated with preassigned playing-keys of said keyboard. The combination of instrumentalities set forth in said patent enables piano music and organ-like music to be played separately or together at the will of the player and from a common keyboard.

As distinguished from the characterizing features of the disclosure in said patent, my invention has for its primary object the provision of an exceedingly compact organization of electrically inter-connected or coupled parts including audio signal generating devices, control mechanisms and signal amplifying and reproducing mechanisms which are designed and adapted to be self-contained in the case of most any vertical piano, in which said piano only a very minimum of surplus space remains for the accommodation of anything other than the actual working parts of the piano. 1

Certain essential objects of the invention are:

l. The provision of a combined musical instrument in which the audio signal generating devices and the signal amplifying and reproducing mechanisms are adapted to be mounted on a removable structural section of the case of a piano, such, for example, the customary kneeboard and completely accommodated and housed in the case and whereby, the above named devices and mechanisms are separable as a common unit from other electrically coactive parts of the invention and can be removed from the case with the kneeboard and in like manner regenerating and translating mechanisms which can be quickly attached to and removed from a vertical piano with great ease and convenience.

4. The provision of an organization of the class and for the purpose set forth which is of light weight, compact and takes no more floor space than the piano itself.

5. The provision of a combined keyboard musical instrument, the case of which provides an eifective acoustical chamber for improved quality of the electrically produced sounds.

6. The provision of means for electrically producing sustained organ-like tones, which said means, when combined with an vertical piano, will not detract from the ornamental and refined finish of the case.

Further novel features of my invention are set forth with particularity in the hereto appended claims. The invention, however, both as to the herein disclosed organization of electrically coactive parts and their advantages, will be fully understood from the following description of one embodiment of my invention taken in connection with the accompanying drawings in which:

Figure l is a perspective view of a vertical piano having my invention embodied therein as a builtin part thereof;

.Figure 2 is a schematic view of the organization showing the audio signal generating means, the audio amplifier and the loud speaker attached to the inner face of the kneeboard of a piano and illustrating the key switch assembly and the conductor cable for electrically connecting the switches of said assembly with the signal generating means and the audio amplifier in such a manner that all parts except said switch assembly can be removed as a unit together with the kneeboard for the purpose of free and easy access to said parts and whereby said parts will be self-contained in the case when the kneeboard is applied;

sembly by preassigned playing-keys of the instruments keyboard;

Figure 5 is a schematic view of the electrically coactive mechanisms of the invention;

.musical range .cf five octaves.

Figure 6 is a schematic view of one of the divider circuits of the frequency generating system.

In carrying the invention into practice any well known tone frequency generating mechanism may be employed wherein provision is made for generating audio tone signals corresponding with-the vibration frequencies of different notes ofthechromatic'scale embracing morethan a single octave of notes and in which system, provision is made for amplifying said signals and translating same into audible sounds .for musical expression. Patents Nos. 2,403,093 and 2,410,883 disclose systems of this general -.,-class that can be and have been found fully satisfactory for the purpose of mysinvention. The :invention is primarily designed, adapted and intended for use in combination with a piano or other keyboard musical instrument according to the broad teaching in Letters Patent No. 2,250,065 wherein tuned-electron discharge devices respectively produce audio frequency output waves .of given tone ,frequency and are connected in key- :ing'circuits for selective conductionof said out- .put waves to .an audio amplifier for amplification thereof sufficiently to activate a loud speaker, .allof avhich can-be accomplished selectively from thekeyboardcof the piano.

.At :Figure 6 .of the accompanying drawings there is shown ,a divider circuit of the class set forth. said Patents Nos. 2,403,093 and 2,410,883. There will be twelve such circuits respectively providing a .full frequency complement for a For all notes of the same letter there is .a cascade ofoscillator stages operating at octave separation, such that there is .a cascade producing audio signals having the vibration frequencies ,for all C notes, .a cascade vprovidingaudio signals having the vi .bra-ticn frequencies .for all .Cii notes and so on toand inclusive of .a. cascadeproducing audio :fre- .auencies for all .33 notes. The aforementioned keying circuits preferably embody electric switches of the type disclosed in United .States .Letters Patent ,No. 2,487,977.

The C note cascade shownat Figure '6 consists of oscillator stages A, B, .C,.D .and .E in which .stageAoscillates at.a controlled natural frequency. .In the .present embodiment .this

stage .may.be .called the master stage as .it will oscillate at a frequency higher than ,all of the succeeding stages of said cascade. Stage .B oscillates at l a-frequency one-half that of the master stage A and so onto and vinclusiveofstage ..E which oscillatesatone-half the frequency of the preceding .stage D. For a keyboard the gamut of which embraces .five octaves the fre- Iquencyrange of .said cascade willlibe substan- .tially from Cz =.65.--cyc1es to C=l975.-cycles.

.Each of these stages A-E 'has an output terminal 50 for connection to respective .switches .ofthe switch'assembly to be hereinafter referred .at 2a. Thenumeral eidesignates an audio amplifier wired at 3a to said wave .filter system and 5 is a loud speaker connected at 5a to amplifier 4. The wave filter system may be of the type shown in said Patent No. 2,403,093. The tone frequency generators disclosed in said patent each produce a complex wave which is rich in harmonics. The wave filter system functions to repeat said complex waves as less complex waves, which, by se- --lective.manipulation of -s-t-ops can-:sbe impressed on theiaudioamplifierforactivation of said loud speaker. No claim is made for any of the above anechanisms except in the combination and for use in the disclosed environment of my invention.

Referring now to :Figure 2, the twelve cascades .o-fgenerators :CpCi D, Di, E, F, Ft, (3-, Gt, A, At .and: B,-each-consisting of five oscillator stages as ,previouslysetforth are suitably attached to the "inner'face of the kneeboard B of the case I of the ;;piano P. The power amplifier 4 and the loud speaker 5 are similarly mounted on the inner-face .of-.-said kneeboard .5. Thekneeboard 6 :has an opening .23 passing transversely there- .throngh. The loud speaker is in horizontal alignment with said opening .and arranged so that the .frontof the cone of the speaker is directlyin back ofsaid opening so that sound at .the speaker will be projected in a forward direction fro-msaid kneeboard. .Sound from in back of the cone .is effective inside thecase of the piano, ithaving-been discovered that the space in said case functions .in a highly satisfactory manner 'as .an acoustical chamber for enrichmentof the electrically produced sound. Sound from inside the case may be projected to the atmosphere by merely opening the customary top of the caseto any desired extent.

.At .Q-en the generator assembly 1 shown at 'Eigure 2..is .a .multiple contact socket member, the individualcontacts of which are wired to the respectiveoscillator stages of the twelve cascades ofstages.

Thekey switch assembly ,9?) comprises a horizontal .rowiof longitudinally spaced apart electric switches 9a supported by a metal bar I0. Theendsof said bar are mounted at II to the .bed .plank of the piano at points beyond the exvtreme ends .of the keyboard as will be clearly understood upon referring .to Figure 4 of the drawings. The .bar is thus fixed at .a desired elevationinside the case of the piano and above the .backqendsof the playing-keys and the spacingbetween the switches is such that .foreach givenplaying-key there is an electric switch individual thereto and adapted .to be operated to an fon condition .upondepressing said key. These keying switches are preferably of the "kind set .iorthinPatentNo. 2,487,977 and are intended to function precisely the same as the playing key operated switches disclosed in Patent No. 2,250,065,. i. ,e., when the playing-keys are raised, the switches will be in off conditions of adjustment and in on positions of adjustment when the keys are depressed.

The individual output conductors which connect the keying switches in circuit with respective oscillator stages are formed into a cable l2 as shown at Figure2. One end of the cable has a multiple contact plug t3 consisting of 60 contactors which are complementary to the contactors of the-aforementioned socket 9. It follows from this arrangement that the socket member '9 can be detached from the plug 13 for removal of the kneeboard 6 from the piano. When the plug is connected to thesocket the cur- -rent flow from the respective generators C-B will be through the conductors of the cable and to the individual switches 9a of said switch assembly. Upon referring to Figure 6 it is noted that the terminals 50 at the outputs of the stages A-E are connected to leads 60 that include the switches 9a and that these switches are connected to an output conductor 90. Referring again to Figure 2, the output conductor 90 is embodied in a branch [2a of cable 12. Said branch lZa is provided with a plug 12b for detachable connection with a socket M of the wave filter system.

The wave filter system 3 forms a part of a quality control device [5 which is mounted in front of the piano where it is accessible to the player. Said device may have as many stops [6 as there are filters in said system and these can be of any conventional construction that will cause conduction of the output waves from said filters to the amplifier 4. At 4a in Figure 5 the amplifier is provided with a conventional volume control device, which, in practice can be situated at said quality control device where it can be operated by the knee of the player.

From the foregoing description it follows that all parts of the organization may be removed with the kneeboard by simply disconnecting plugs I21) and 13 from plugs 14 and 9, leaving the entire switch assembly in its normal horizontally disposed fixed position in the case of the piano. The generators, amplifier and the loud speaker are of minimum proportions and extend rearwardly from the inner face of the kneeboard only a few inches, thereby enabling them to be nicely accommodated in the space in front of the string plate of the piano and immediately in back of the kneeboard.

What I claim is:

1. A portable, self-contained, combined musical instrument, comprising, a vertical piano including an enclosing case having a horizontally disposed bed plank supporting the keyboard of said piano and a removably mounted kneeboard which is tiltable from a vertical position of closed adjustment against the case and underneath said kneeboard to a forwardly and downwardly extended angular position of opened adjustment underneath said bed plank and vice versa; a system comprising means for 8180- trically generating audio frequencies of notes of l the chromic scale and means for translating said frequencies into audible sounds for musical expression, said system being mounted on the inner face of said kneeboard for concealment thereof within the case when the kneeboard is in the aforementioned position of vertical closed adjustment against the case and to expose said system underneath the bed plank when the kneeboard is tilted forwardly and downwardly as aforementioned, a set of electric switches mounted inside said case, the individual switches of which are connected to said system and correlated to respective keys of the keyboard of while the kneeboard is tilted in said opposite direction.

3. Mechanism according to claim 1, wherein said network has means enabling disconnectin said tone generating and translating system from the switches of said set of switches for removal of said system from and application thereof to the case together with the kneeboard as a unitary structure.

4. In an organization of the class and for the purpose set forth, a vertical piano including a case and a bed plank and having a removable vertically disposed kneeboard presenting a plano-back surface and a plano-front surface, said kneeboard being tiltable downwardly and forwardly as desired so that said back planosurface faces upwardly towards the underside of the bed plank of the case of the piano and in spaced apart relation thereto, and means actuable from the keyboard of the piano for producing audible sustaining tones, said means including electric switches mounted in said case for actuation from the playing keys of said keyboard, and a set of electrically-controlled tonegenerating sources mounted on said Planoback surface of said kneeboard so as to be Wholly contained in said case when the kneeboard is in a vertical position and exposed underneath the bed plank when the kneeboard is tilted downwardly and forwardly, said sources including adjustable tuning means also mounted on said kneeboard and means including tone signal conductors detachably connecting said switches to said sustained tone-producing means to enable detachment of said switches therefrom, thereby enabling removal of the kneeboard from said case.

WALTER J. ANDERSON.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date D.112,981 Ansley Jan. 24, 1939 849,559 Norcross Apr. 9, 1907 1,988,132 Murray Jan. 15, 1935 2,471,534 Muth May 31, 1949 2,498,898 Rieth Feb. 28, 1950 2,555,040 Jordan May 29, 1951 

